Dependent Types Dynamics in NLS DTS Conclusion
Dependent Types
and
Dynamics of Natural Language
Daisuke Bekki
Ochanomizu University, Faculty of Core Science
A talk at Inui Lab, Tohoku University
27 July, 2022.
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Dependent Types Dynamics in NLS DTS Conclusion
Dependent Type Semantics (DTS) (Bekki 2014;
Bekki and Mineshima 2017; Bekki 2021)
I A framework of natural language semantics
I Unified approach to general inferences and
anaphora/presupposition resolution in terms of proof
construction (cf. Krahmer and Piwek (1999))
Main features:
1. Proof-theoretic semantics:
From truth-conditions (denotations, models) to
proof-conditions (proofs, contexts)
2. Underspecification Semantics: A proof-theoretic alternative
to Dynamic Semantics (DRT, DPL, etc.)
3. Compositional semantics: Syntax-semantics interface via
categorial grammars (e.g. CCG, Hybrid-TLCG)
4. Computational semantics: Implementation, Applications to
Natural Language Processing
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Dependent Types Dynamics in NLS DTS Conclusion
Dependent Types
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Dependent Types Dynamics in NLS DTS Conclusion
Per Martin-Löf
Martin-Löf (1984) “Intuitionistic type theory”
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Dependent Types Dynamics in NLS DTS Conclusion
What are Π-types
Π-type is a type of fibred functions.
Simple function space Fibred function space
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Dependent Types Dynamics in NLS DTS Conclusion
What are Σ-types
Σ-type is a type of fibred products.
Simple product space Fibred product space
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Dependent Types Dynamics in NLS DTS Conclusion
Notations
DTS notation Standard notation x 6∈ fv(B) x ∈ fv(B)
(x : A) → B (Πx : A)B A → B (∀x : A)B
(x : A) × B
or

x : A
B
 (Σx : A)B A ∧ B (∃x : A)B
Scope of the variable in Π-types: (x : A) → B
Scope of the variable in Σ-types:

x : A
B

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Dependent Types Dynamics in NLS DTS Conclusion
Π-type F/I/E rules
A : type
x : A
i
.
.
.
.
B : type
(x : A) → B : type
(ΠF),i
A : type
x : A
i
.
.
.
.
M : B
λx.M : (x : A) → B
(ΠI ),i
M : (x : A) → B N : A
MN : B[N/x]
(ΠE)
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Dependent Types Dynamics in NLS DTS Conclusion
Σ-type F/I/E rules
A : type
x : A
i
.
.
.
.
B : type
(x : A) × B : type
(ΣF),i
M : A N : B[M/x]
(M, N) : (x : A) × B
(ΣI )
M : (x : A) × B
π1(M) : A
(ΣE)
M : (x : A) × B
π2(M) : B[π1(M)/x]
(ΣE)
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Dependent Types Dynamics in NLS DTS Conclusion
Rules of DTS
Rules from Martin-Löf Type Theory
I Axioms and Structural rules
I Π-type (Dependent function type) [F/I/E]
I Σ-type (Dependent product type) [F/I/E]
I Intensional equality type [F/I/E]
I Disjoint union type [F/I/E]
I Enumeration type [F/I/E]
I Natural number type [F/I/E]
New rule in DTS
I @ (the ‘asperand’ operator)
I Anaphora and presupposition triggers
(linguistically speaking)
I Open proofs (logically speaking)
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Dependent Types Dynamics in NLS DTS Conclusion
Conjunction, Implication, and Negation
Definition

A
B

def
≡ (x : A) × B where x /
∈ fv(B).
A → B
def
≡ (x : A) → B where x /
∈ fv(B).
¬A
def
≡ (x : A) → ⊥
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Dependent Types Dynamics in NLS DTS Conclusion
Dynamics in Natural Language
Semantics
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Dependent Types Dynamics in NLS DTS Conclusion
A theory of anaphora
I Anaphora representable by a constant symbol:
I Deictic use:
(1) (Pointing at John)
He was born in Detroit.
bornIn( j , d)
I Coreference:
(2) John loves a girl who hates him .
∃x(girl(x) ∧ love( j , x) ∧ hate(x, j ))
I Anaphora representable by a variable
I Bound variable anaphora:
(3) Every boy loves his father.
∀x (boy(x) → love(x, fatherOf( x )))
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Dependent Types Dynamics in NLS DTS Conclusion
A theory of anaphora
I Anaphora not representable by FoL:
I E-type anaphora:
(4) A man entered into the park. He whistled.
I Donkey anaphora:
(5) Every farmer who owns a donkey beats it .
(6) If a farmer owns a donkey , he beats it .
I Anaphora not representable by FoL nor dynamic semantics:
I Syllogistic anaphora:
(7) Every girl received a present . Some girl opened it .
I Disjunctive antecedent:
(8) If Mary sees a horse or a pony , she waves to it .
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Dependent Types Dynamics in NLS DTS Conclusion
E-type anaphora: Evans (1980)
(9) [A man]1 entered. He1 whistled.
The first-order SR (10) represents the truth condition of (9), thus
is a candidate of the SR of (9).
(10) ∃x(man(x) ∧ enter(x) ∧ whistle(x))
But the syntactic structure of the SR (10) does not correspond to
that of (9), where consists of two independent sentences. The
sentential boundary of (9) prefers the first-order
representation (11).
(11) ∃x(man(x) ∧ enter(x)) ∧ whistle( x )
However, the truth condition of (11) is different from that of the
mini-discourse (9) since the variable x in whistle(x) is not bound
by ∃.
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Dependent Types Dynamics in NLS DTS Conclusion
Donkey anaphora: Geach (1962)
For the donkey sentences (12), a first-order formula (13), whose
truth condition is the same as those of (12), is a candidate of its
SR.
(12) a. Every farmer who owns [a donkey]1 beats it1.
b. If [a farmer]1 owns [a donkey]2 , he1 beats it2.
(13) ∀x(farmer(x) → ∀y (donkey(y) ∧ own(x, y) →
beat(x, y)))
But the translation from the sentence (12) to (13) is not
straightforward since i) the indefinite noun phrase a donkey is
translated into a universal quantifier in (13) instead of an
existential quantifier, and ii) the syntactic structure of (13) does
not corresponds to that of (12).
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Dependent Types Dynamics in NLS DTS Conclusion
Donkey anaphora: Geach (1962)
(12) a. Every farmer who owns [a donkey]1 beats it1 .
b. If [a farmer]1 owns [a donkey]2, he1 beats it2 .
The syntactic parallel of (12) is, rather, the SR (14), in which the
indefinite noun phrase is translated into an existential
quantification.
(14) ∀x(farmer(x) ∧ ∃y(donkey(y) ∧ own(x, y)) →
beat(x, y ))
However, (14) does not represent the truth condition of (12)
correctly since the variable y in beat(x, y) fails to be bound by ∃.
Therefore, neither (13) nor (14) qualifies as the SR of (12).
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Dependent Types Dynamics in NLS DTS Conclusion
E-type anaphora: Ranta (1994)
(9) A man entered. He whistled.







u :



x : entity

man(x)
enter(x)




whistle( π1(u) )







Note:

x : A
B

is a type for pairs of A and B[x].
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Dependent Types Dynamics in NLS DTS Conclusion
Donkey anaphora: Sundholm (1986)
(12a) Every farmer who owns a donkey beats it .







u :







x : entity





farmer(x)



v :

y : entity
donkey(y)
#
own(x, π1v)






















→ beat(π1u, π1π1π2π2u
Note: (x : A) → B is a type for functions from A to B[x].
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Dependent Types Dynamics in NLS DTS Conclusion
From TTG to DTS: Compositionality
Q: How could one get to these (dependently-typed)
representations from arbitrary sentences?
A: By lexicalization.
Q: How could we lexicalize context-dependent words like
pronouns?







u :



x : entity

man(x)
enter(x)




whistle( π1(u) )







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Dependent Types Dynamics in NLS DTS Conclusion
Dependent Type Semantics (DTS)
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Dependent Types Dynamics in NLS DTS Conclusion
From TTG to DTS: Compositionality
Q: How could one get to these (dependently-typed)
representations from arbitrary sentences?
A: By lexicalization.
Q: How could we lexicalize context-dependent words like
pronouns?
A: By using underspecified terms.
Q: But how could we retrieve a context for an
underspecified term?
A: By type checking.
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Dependent Types Dynamics in NLS DTS Conclusion
Underspecified terms
DTS = DTT + underspecified terms @A
Definition (@-rule)
A : typej A true
@iA : A
where j ∈ N
(@)
I @-rule states that the well-formedness of @A requires:
I A is a well-formed type.
I the inhabitance of A (namely, A is a presuppositional content)
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Dependent Types Dynamics in NLS DTS Conclusion
On parsing
We assume that an SR of a sentence is obtained by parsing and
semantic composition (assumed by one’s syntactic theory).
A sentence
⇓
Parsing
⇓
An underspecified SRs in DTS
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Dependent Types Dynamics in NLS DTS Conclusion
Lexical items in CCG-style
PF CCG categories Semantic representations in DTS
if S/S/S λp.λq. (u : p) → q
everynom S/(SNP)/N λn.λp.

u :

x : entity
nx

→ p(π1(u))
everyacc T (T /NP)/N λn.λp.λ~
x.

v :

y : entity
ny

→ p(π1(v))~
x
anom , somenom S/(SNP)/N λn.λp.

 u :

x : entity
nx

p(π1(u))


aacc, someacc T (T /NP)/N λn.λp.λ~
x.

 v :

y : entity
ny

p(π1(v))~
x


farmer N farmer
donkey N donkey
who NN/(SNP ) λp.λn.λx.

nx
px

whom NN/(S/NP ) λp.λn.λx.

nx
px

owns SNP/NP own
beats SNP/NP beat
he NP π1 @

x : entity
male(x)
 !
it NP π1 @

x : entity
¬human(x)
 !
the NP/N λn.π1 @

x : entity
nx
 !
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Dependent Types Dynamics in NLS DTS Conclusion
Lexical items in CCG-style (anaphoric expressions)
PF CCG categories Semantic representations in DTS
he NP π1 @

x : entity
male(x)
 !
it NP π1 @

x : entity
¬human(x)
 !
the NP/N λn.π1 @

x : entity
nx
 !
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Dependent Types Dynamics in NLS DTS Conclusion
E-type anaphora: Parsing
A
S/(SNP)/N
: λn.λp.

 u :

x : entity
nx

p(π1u)


man
N
: λx.man(x)
S/(SNP)
: λp.

 u :

x : entity
man(x)

p(π1u)



entered
SNP
: λx.enter(x)
S
:

 u :

x : entity
man(x)

enter(π1u)



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Dependent Types Dynamics in NLS DTS Conclusion
E-type anaphora: Parsing
He
NP
: π1 @

x : entity
male(x)

whistled
SNP
: λx.whistle(x)
S
: whistle π1 @

x : entity
male(x)
 !

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Dependent Types Dynamics in NLS DTS Conclusion
Progressive conjunction: Ranta (1994)
Definition (Progressive conjunction)
M; N
def
≡

u : M
N

where u /
∈ fv(N)
(9) [A man]1 entered. He 1 whistled.


x : entity

man(x)
enter(x)


 ; whistle(π1 @

x : entity
male(x)

)
=







u :


x : entity

man(x)
enter(x)



whistle(π1 @

x : entity
male(x)

)







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Dependent Types Dynamics in NLS DTS Conclusion
E-type anahora: Type checking
.
.
.

 u :

x : entity
man(x)

enter(π1u)

 : type
whistle
: entity
→ type
(CON )
.
.
.

x : entity
male(x)

: type
v :

 u :

x : entity
man(x)

enter(π1u)


1
.
.
.
.

x : entity
male(x)

true
@

x : entity
male(x)

:

x : entity
male(x)
 (@)
π1 @

x : entity
male(x)

: entity
(ΣE)
whistle π1 @

x : entity
male(x)
 !
: type
(→E)







v :

 u :

x : entity
man(x)

enter(π1u)



x : entity
 !







: type
(ΣF),1
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Dependent Types Dynamics in NLS DTS Conclusion
E-type anaphora: Proof search
v :

 u :

x : entity
man(x)

enter(π1u)


1
π1v :

x : entity
man(x)
 (ΣE)
π1π1v : entity
(ΣE)
v :

 u :

x : entity
man(x)

enter(π1u)


1
π1v :

x : entity
man(x)
 (ΣE)
m :

u :

x : entity
man(x)

→ male(π1
m(π1v) : male(π1π1v)
(π1π1v, m(π1v)) :

x : entity
male(x)
 (ΣE)
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Dependent Types Dynamics in NLS DTS Conclusion
E-type anaphora: @-elimination
.
.
.
.

 u :

x : entity
man(x)

enter(π1u)

 : type
whistle : entity → type
v :

 u :

x : entity
man(x)

enter(π1u)


1
.
.
.
.
(π1π1v, m(π1v)) :

x : entity
male(x)

π1π1v : entity
(ΣE)
whistle( π1π1v ) : type
(ΠE)




v :

 u :

x : entity
man(x)

enter(π1u)


whistle( π1π1v )



 : type
(ΣF),1
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Dependent Types Dynamics in NLS DTS Conclusion
@-elimination rules
Definition (@-elimination rules (excerpt))
u
w
vA : s
DM
M : A0
@iA : A
(@)
}

~ =
DM
M : A0
u
w
w
v
DA
A : s1
x : A0
DB
B : s2
(x : A) → B : s2
(ΠF)
}


~ =
JDAK
A0 : s1
x : A0
JDBK
B0 : s2
(x : A0) → B0 : s2
(ΠF)
u
w
w
v
DA
A : s1
x : A0
DM
M : B
λx.M : (x : A) → B
(ΠI )
}


~ =
JDAK
A0 : s1
x : A0
JDM K
M0 : B0
λx.M0 : (x : A0) → B0
(ΠI )
u
w
v
DM
M : (x : A) → B
DN
N : A
MN : B0
(ΠE)
}

~ =
JDM K
M0 : (x : A0) → B0
JDN K
N0 : A0
M0N0 : B00
where B0[N0/x] β B00
(ΠE)
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Dependent Types Dynamics in NLS DTS Conclusion
The model of language understanding
A sentence . . . A sentence
⇓ ⇓
Parsing . . . Parsing
⇓ ⇓
An underspecified SRs in DTS . . . An underspecified SRs in DTS
⇓ ⇓
Discoruse relation (e.g. Progressive conjunction)
⇓
An underspecified discourse representation in DTS
⇓
Type checking + Proof search in DTS
⇓
A proof diagram of the well-formedness of an SR in DTS
⇓
@-elimination
⇓
A proof diagram of the well-formedness of an SR in DTT
⇓
Inference in DTT
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Dependent Types Dynamics in NLS DTS Conclusion
Concluding Remarks
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Dependent Types Dynamics in NLS DTS Conclusion
Compositional Theory of Anaphora
I DTS provides a unified analysis for (general) inferences and
anaphora resolusion mechanisms (at least) for:
I Deictic use and coreference
I Bound variable anaphora (BVA)
I E-type anaphora
I Donkey anaphora
I Bridging anaphora
I Syllogistic anaphora
I Disjunctive antecedents
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Dependent Types Dynamics in NLS DTS Conclusion
Compositional Theory of Anaphora
I The background theory for DTS is an extention of DTT with
underspecified terms and the @-rule .
I Lexical items of anaphoric expressions and presupposition
triggers are represented by using underspecified terms.
I Context retrieval in DTS reduces to type checking .
I Anaphora resolution and presupposition binding in DTS
reduces to proof search .
I @-elimination translates a proof diagram of DTS into a proof
diagram of DTT, by which an SR in DTT is obtained with all
anaphora resolved.
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Dependent Types Dynamics in NLS DTS Conclusion
Natural language semantics via dependent types:
Classics
I Donkey anaphora: Sundholm (1986)
I Translation from DRS to dependent type representations: Ahn
and Kolb (1990)
I Summation: Fox (1994a,b)
I Ranta’s TTG (Relative and Implicational Donkey Sentences,
Branching Quantifiers, Intensionality, Tense): Ranta (1994)
I Translation from Montague Grammar to dependent type
representations: Dávila-Pérez (1995)
I Presupposition Binding and Accommodation, Bridging:
Krahmer and Piwek (1999), Piwek and Krahmer (2000)
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Dependent Types Dynamics in NLS DTS Conclusion
Natural language semantics via dependent types:
Recent frameworks
I Type Theory with Record (TTR): Cooper (2005)
I Modern Type Theory: Luo (1997, 1999, 2010, 2012), Asher
and Luo (2012), Chatzikyriakidis (2014)
I Semantics with Dependent Types: Grudzinska and
Zawadowski (2014; 2017)
I Dependent Type Semantics (DTS): Bekki (2014), Bekki
and Mineshima (2017)
I (Dynamic Categorial Grammar: Martin and Pollard (2014))
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Dependent Types Dynamics in NLS DTS Conclusion
Semantic Analyses by DTS
I Generalized Quantifiers: Tanaka (2014)
I Honorification: Watanabe et al. (2014)
I Conventional Implicature: Bekki and McCready (2015)
I Factive Presuppositions: Tanaka et al. (2015)(2017)
I Dependent Plural Anaphora: Tanaka et al. (2017)
I Paycheck sentences: Tanaka et al. (2018) in NLCS2018 (July
7)
I Coercion and Metaphor: Kinoshita et al. (2018)
I Questions in Dependent Type Semantics: Watanabe et al.
(NLCS’19)
I Comparision with DRT: Yana et al. (2019) in JoLLI
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Dependent Types Dynamics in NLS DTS Conclusion
Semantic Analyses by DTS
I Development of an automated theorem prover for the
fragment of DTS: Daido and Bekki (2020) in LENLS17
I A Proof-theoretic Analysis of Weak Crossover: Bekki (2021)
in LENLS18
I The proviso problem from a proof-theoretic perspective: Yana
et al. (2021) in LACL2021
I Integrating Deep Neural Network with Dependent Type
Semantics: Bekki et al. (2021) in LACompLing2021
I Learning Knowledge with Neural DTS: Bekki et al. (2022) in
NALOMA’22
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Dependent Types Dynamics in NLS DTS Conclusion
Thank you!
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Typing Rules @-Elim. Rules References
Typing Rules in DTS
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Typing Rules @-Elim. Rules References
Axioms and Structural Rules
A : type
x : A
(VAR)
c : A
(CON )
where σ ` c : A.
M : A N : B
M : A
(WK)
M : A
M : B
(CONV )
where A =β B.
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Typing Rules @-Elim. Rules References
Π-type F/I/E rules
A : type
x : A
i
.
.
.
.
B : type
(x : A) → B : type
(ΠF),i
A : type
x : A
i
.
.
.
.
M : B
λx.M : (x : A) → B
(ΠI ),i
M : (x : A) → B N : A
MN : B[N/x]
(ΠE)
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Typing Rules @-Elim. Rules References
Σ-type F/I/E rules
A : type
x : A
i
.
.
.
.
B : type
(x : A) × B : type
(ΣF),i
M : A N : B[M/x]
(M, N) : (x : A) × B
(ΣI )
M : (x : A) × B
π1(M) : A
(ΣE)
M : (x : A) × B
π2(M) : B[π1(M)/x]
(ΣE)
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Typing Rules @-Elim. Rules References
Disjoint Union Type F/I/E rules
A : type B : type
A ] B : type
(]F)
M : A
ι1(M) : A ] B
(]I )
N : B
ι2(N) : A ] B
(]I )
L : A ] B P : (A ] B) → type M : (x : A) → P (ι1(x)) N : (x
unpackP
L (M, N) : P (L)
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Typing Rules @-Elim. Rules References
Natural Number Type F/I/E rules
N : type
(NF)
0 : N
(NI )
n : N
s(n) : N
(NI )
n : N P : N → type e : P (0) f : (k : N) → P (k) → P (s(k))
natrecP
n (e, f) : P (n)
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Typing Rules @-Elim. Rules References
Enumeration Type F/I/E rules
{a1, . . . , an} : type
({}F)
ai : {a1, . . . , an}
({}I )
M : {a1, . . . , an} P : {a1, . . . , an} → type N1 : P (a1) . . . Nn : P (an)
caseP
M (N1, . . . , Nn) : P (M)
({}E)
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Typing Rules @-Elim. Rules References
Intensional Equality Type F/I/E rules
A : type M : A N : A
M =A N : type
(=F)
A : type M : A
reflA(M) : M =A M
(=I )
E : M =A N P : (x : A) → (y : A) → (x =A y) → type R : (x : A) → P xx(reflA(x))
idpeelP
E (R) : P MNE
(=
50 / 61
Typing Rules @-Elim. Rules References
@-rule
A : typej A true
@iA : A
where j ∈ N
(@)
51 / 61
Typing Rules @-Elim. Rules References
@-Elimination Rules in DTS
52 / 61
Typing Rules @-Elim. Rules References
Axioms
u
w
vA : s
DM
M : A0
@iA : A
(@)
}

~ =
DM
M : A0
s
c : A
(CON )
{
= c : A
(CON )
r
x : A
z
= x : A
s
type : kind
(typeF)
{
= type : kind
(typeF)
53 / 61
Typing Rules @-Elim. Rules References
Π-type
u
w
w
v
DA
A : s1
x : A0
DB
B : s2
(x : A) → B : s2
(ΠF)
}


~ =
JDAK
A0 : s1
x : A0
JDBK
B0 : s2
(x : A0) → B0 : s2
(ΠF)
u
w
w
v
DA
A : s1
x : A0
DM
M : B
λx.M : (x : A) → B
(ΠI )
}


~ =
JDAK
A0 : s1
x : A0
JDM K
M0 : B0
λx.M0 : (x : A0) → B0
(ΠI )
u
w
v
DM
M : (x : A) → B
DN
N : A
MN : B0
(ΠE)
}

~ =
JDM K
M0 : (x : A0) → B0
JDN K
N0 : A0
M0N0 : B00
where B0[N0/x] β B00
(ΠE)
54 / 61
Typing Rules @-Elim. Rules References
Σ-type
u
w
w
w
v
DA
A : s1
x : A0
DB
B : s2

x : A
B

: s2
(ΣF)
}



~
=
JDAK
A0 : s1
x : A0
JDBK
B0 : s2

x : A0
B0

: s2
(ΣF)
u
w
w
v
DM
M : A
DN
N : B0
(M, N) :

x : A
B
 (ΣI )
}


~ =
JDM K
M0 : A0
JDN K
N0 : B000
(M0, N0) :

x : A0
B00

where B00[M0/x] β B000
(ΣI )
u
w
w
w
v
DM
M :

x : A
B

π1(M) : A
(ΣE)
}



~
=
JDM K
M0 :

x : A0
B0

π1(M0) : A0
(ΣE)
u
w
w
w
v
DM
M :

x : A
B

π2(M) : B0
(ΣE)
}



~
=
JDM K
M0 :

x : A0
B00

π2(M0) : B000
(ΣE)
55 / 61
Typing Rules @-Elim. Rules References
Reference I
Ahn, R. and H.-P. Kolb. (1990) “Discourse Representation meets
Constructive Mathematics”, In: L. Kalman and L. Polos (eds.):
Papers from the Second Symposium on Logic and Language.
Akademiai Kiado, pp.1–18.
Asher, N. and Z. Luo. (2012) “Formalisation of coercions in lexical
semantics”, In the Proceedings of Sinn und Bedeutung 17.
pp.63–80.
Bekki, D. (2014) “Representing Anaphora with Dependent Types”,
In the Proceedings of N. Asher and S. V. Soloviev (eds.):
Logical Aspects of Computational Linguistics (8th international
conference, LACL2014, Toulouse, France, June 2014
Proceedings), LNCS 8535. pp.14–29, Springer, Heiderburg.
56 / 61
Typing Rules @-Elim. Rules References
Reference II
Bekki, D. and E. McCready. (2015) “CI via DTS”, In: New
Frontiers in Artificial Intelligence (JSAI-isAI 2014 Workshops,
LENLS, JURISIN, and GABA, Yokohama, Japan, November
23-24, 2014, Revised Selected Papers), Vol. LNAI 9067.
Springer, pp.23–36.
Bekki, D. and K. Mineshima. (2017) “Context-passing and
Underspecification in Dependent Type Semantics”, In: Modern
Perspectives in Type Theoretical Semantics, Studies of
Linguistics and Philosophy. Springer, pp.11–41.
Chatzikyriakidis, S. (2014) “Adverbs in a Modern Type Theory”,
In: N. Asher and S. V. Soloviev (eds.): Logical Aspect of
Computational Linguistics, 8th International Conference,
LACL2014, Toulouse, France, June 18-20, 2014 Proceedings.
Springer.
57 / 61
Typing Rules @-Elim. Rules References
Reference III
Cooper, R. (2005) “Records and Record Types in Semantic
Theory”, Journal of Logic and Computation 15(2), pp.99–112.
Dávila-Pérez, R. (1995) “Semantics and Parsing in Intuitionistic
Categorial Grammar”, Thesis, University of Essex. Ph.D. thesis.
Evans, G. (1980) “Pronouns”, Linguistic Inquiry 11, pp.337–362.
Fox, C. (1994a) “Discourse Representation, Type Theory and
Property Theory”, In the Proceedings of H. Bunt, R. Muskens,
and G. Rentier (eds.): the International Workshop on
Computational Semantics. pp.71–80.
Fox, C. (1994b) “Existence Presuppositions and Category
Mistakes”, Acta Linguistica Hungarica 42(3/4), pp.325–339.
Geach, P. (1962) Reference and Generality: An Examination of
Some Medieval and Modern Theories. Ithaca, New York, Cornell
University Press.
58 / 61
Typing Rules @-Elim. Rules References
Reference IV
Krahmer, E. and P. Piwek. (1999) “Presupposition Projection as
Proof Construction”, In: H. Bunt and R. Muskens (eds.):
Computing Meanings: Current Issues in Computational
Semantics, Studies in Linguistics Philosophy Series. Dordrecht,
Kluwer Academic Publishers.
Luo, Z. (1997) “Coercive subtyping in type theory”, In: D. van
Dalen and M. Bezem (eds.): CSL 1996. LNCS, vol. 1258.
Heidelberg, Springer.
Luo, Z. (1999) “Coercive subtyping”, Journal of Logic and
Computation 9(1), pp.105–130.
Luo, Z. (2010) “Type-theoretical semantics with coercive
subtyping”, In the Proceedings of Semantics and Linguistic
Theory 20 (SALT 20).
59 / 61
Typing Rules @-Elim. Rules References
Reference V
Luo, Z. (2012) “Formal Semantics in Modern Type Theories with
Coercive Subtyping”, Linguistics and Philosophy 35(6).
Martin, S. and C. J. Pollard. (2014) “A dynamic categorial
grammar”, In the Proceedings of Formal Grammar 19, LNCS
8612.
Piwek, P. and E. Krahmer. (2000) “Presuppositions in Context:
Constructing Bridges”, In: P. Bonzon, M. Cavalcanti, and R.
Nossum (eds.): Formal Aspects of Context, Applied Logic
Series. Dordrecht, Kluwer Academic Publishers.
Ranta, A. (1994) Type-Theoretical Grammar. Oxford University
Press.
Sundholm, G. (1986) “Proof theory and meaning”, In: Handbook
of Philosophical Logic, Vol. III. Reidel, Kluwer, pp.471–506.
60 / 61
Typing Rules @-Elim. Rules References
Reference VI
Tanaka, R. (2014) “A Proof-Theoretic Approach to Generalized
Quantifiers in Dependent Type Semantics”, In the Proceedings
of R. de Haan (ed.): the ESSLLI 2014 Student Session, 26th
European Summer School in Logic, Language and Information.
pp.140–151.
Tanaka, R., K. Mineshima, and D. Bekki. (2015) “Factivity and
Presupposition in Dependent Type Semantics”, In the
Proceedings of TYpe Theory and LExical Semantics (TYTLES),
ESSLLI2015 workshop.
Watanabe, N., E. McCready, and D. Bekki. (2014) “Japanese
Honorification: Compositionality and Expressivity”, In the
Proceedings of S. Kawahara and M. Igarashi (eds.): FAJL 7:
Formal Approaches to Japanese Linguistics, the MIT Working
Papers in Linguistics 73. pp.265–276.
61 / 61

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Dependent Types and Dynamics of Natural Language

  • 1. Dependent Types Dynamics in NLS DTS Conclusion Dependent Types and Dynamics of Natural Language Daisuke Bekki Ochanomizu University, Faculty of Core Science A talk at Inui Lab, Tohoku University 27 July, 2022. 1 / 61
  • 2. Dependent Types Dynamics in NLS DTS Conclusion Dependent Type Semantics (DTS) (Bekki 2014; Bekki and Mineshima 2017; Bekki 2021) I A framework of natural language semantics I Unified approach to general inferences and anaphora/presupposition resolution in terms of proof construction (cf. Krahmer and Piwek (1999)) Main features: 1. Proof-theoretic semantics: From truth-conditions (denotations, models) to proof-conditions (proofs, contexts) 2. Underspecification Semantics: A proof-theoretic alternative to Dynamic Semantics (DRT, DPL, etc.) 3. Compositional semantics: Syntax-semantics interface via categorial grammars (e.g. CCG, Hybrid-TLCG) 4. Computational semantics: Implementation, Applications to Natural Language Processing 2 / 61
  • 3. Dependent Types Dynamics in NLS DTS Conclusion Dependent Types 3 / 61
  • 4. Dependent Types Dynamics in NLS DTS Conclusion Per Martin-Löf Martin-Löf (1984) “Intuitionistic type theory” 4 / 61
  • 5. Dependent Types Dynamics in NLS DTS Conclusion What are Π-types Π-type is a type of fibred functions. Simple function space Fibred function space 5 / 61
  • 6. Dependent Types Dynamics in NLS DTS Conclusion What are Σ-types Σ-type is a type of fibred products. Simple product space Fibred product space 6 / 61
  • 7. Dependent Types Dynamics in NLS DTS Conclusion Notations DTS notation Standard notation x 6∈ fv(B) x ∈ fv(B) (x : A) → B (Πx : A)B A → B (∀x : A)B (x : A) × B or x : A B (Σx : A)B A ∧ B (∃x : A)B Scope of the variable in Π-types: (x : A) → B Scope of the variable in Σ-types: x : A B 7 / 61
  • 8. Dependent Types Dynamics in NLS DTS Conclusion Π-type F/I/E rules A : type x : A i . . . . B : type (x : A) → B : type (ΠF),i A : type x : A i . . . . M : B λx.M : (x : A) → B (ΠI ),i M : (x : A) → B N : A MN : B[N/x] (ΠE) 8 / 61
  • 9. Dependent Types Dynamics in NLS DTS Conclusion Σ-type F/I/E rules A : type x : A i . . . . B : type (x : A) × B : type (ΣF),i M : A N : B[M/x] (M, N) : (x : A) × B (ΣI ) M : (x : A) × B π1(M) : A (ΣE) M : (x : A) × B π2(M) : B[π1(M)/x] (ΣE) 9 / 61
  • 10. Dependent Types Dynamics in NLS DTS Conclusion Rules of DTS Rules from Martin-Löf Type Theory I Axioms and Structural rules I Π-type (Dependent function type) [F/I/E] I Σ-type (Dependent product type) [F/I/E] I Intensional equality type [F/I/E] I Disjoint union type [F/I/E] I Enumeration type [F/I/E] I Natural number type [F/I/E] New rule in DTS I @ (the ‘asperand’ operator) I Anaphora and presupposition triggers (linguistically speaking) I Open proofs (logically speaking) 10 / 61
  • 11. Dependent Types Dynamics in NLS DTS Conclusion Conjunction, Implication, and Negation Definition A B def ≡ (x : A) × B where x / ∈ fv(B). A → B def ≡ (x : A) → B where x / ∈ fv(B). ¬A def ≡ (x : A) → ⊥ 11 / 61
  • 12. Dependent Types Dynamics in NLS DTS Conclusion Dynamics in Natural Language Semantics 12 / 61
  • 13. Dependent Types Dynamics in NLS DTS Conclusion A theory of anaphora I Anaphora representable by a constant symbol: I Deictic use: (1) (Pointing at John) He was born in Detroit. bornIn( j , d) I Coreference: (2) John loves a girl who hates him . ∃x(girl(x) ∧ love( j , x) ∧ hate(x, j )) I Anaphora representable by a variable I Bound variable anaphora: (3) Every boy loves his father. ∀x (boy(x) → love(x, fatherOf( x ))) 13 / 61
  • 14. Dependent Types Dynamics in NLS DTS Conclusion A theory of anaphora I Anaphora not representable by FoL: I E-type anaphora: (4) A man entered into the park. He whistled. I Donkey anaphora: (5) Every farmer who owns a donkey beats it . (6) If a farmer owns a donkey , he beats it . I Anaphora not representable by FoL nor dynamic semantics: I Syllogistic anaphora: (7) Every girl received a present . Some girl opened it . I Disjunctive antecedent: (8) If Mary sees a horse or a pony , she waves to it . 14 / 61
  • 15. Dependent Types Dynamics in NLS DTS Conclusion E-type anaphora: Evans (1980) (9) [A man]1 entered. He1 whistled. The first-order SR (10) represents the truth condition of (9), thus is a candidate of the SR of (9). (10) ∃x(man(x) ∧ enter(x) ∧ whistle(x)) But the syntactic structure of the SR (10) does not correspond to that of (9), where consists of two independent sentences. The sentential boundary of (9) prefers the first-order representation (11). (11) ∃x(man(x) ∧ enter(x)) ∧ whistle( x ) However, the truth condition of (11) is different from that of the mini-discourse (9) since the variable x in whistle(x) is not bound by ∃. 15 / 61
  • 16. Dependent Types Dynamics in NLS DTS Conclusion Donkey anaphora: Geach (1962) For the donkey sentences (12), a first-order formula (13), whose truth condition is the same as those of (12), is a candidate of its SR. (12) a. Every farmer who owns [a donkey]1 beats it1. b. If [a farmer]1 owns [a donkey]2 , he1 beats it2. (13) ∀x(farmer(x) → ∀y (donkey(y) ∧ own(x, y) → beat(x, y))) But the translation from the sentence (12) to (13) is not straightforward since i) the indefinite noun phrase a donkey is translated into a universal quantifier in (13) instead of an existential quantifier, and ii) the syntactic structure of (13) does not corresponds to that of (12). 16 / 61
  • 17. Dependent Types Dynamics in NLS DTS Conclusion Donkey anaphora: Geach (1962) (12) a. Every farmer who owns [a donkey]1 beats it1 . b. If [a farmer]1 owns [a donkey]2, he1 beats it2 . The syntactic parallel of (12) is, rather, the SR (14), in which the indefinite noun phrase is translated into an existential quantification. (14) ∀x(farmer(x) ∧ ∃y(donkey(y) ∧ own(x, y)) → beat(x, y )) However, (14) does not represent the truth condition of (12) correctly since the variable y in beat(x, y) fails to be bound by ∃. Therefore, neither (13) nor (14) qualifies as the SR of (12). 17 / 61
  • 18. Dependent Types Dynamics in NLS DTS Conclusion E-type anaphora: Ranta (1994) (9) A man entered. He whistled.        u :    x : entity man(x) enter(x)    whistle( π1(u) )        Note: x : A B is a type for pairs of A and B[x]. 18 / 61
  • 19. Dependent Types Dynamics in NLS DTS Conclusion Donkey anaphora: Sundholm (1986) (12a) Every farmer who owns a donkey beats it .        u :        x : entity      farmer(x)    v : y : entity donkey(y) # own(x, π1v)                       → beat(π1u, π1π1π2π2u Note: (x : A) → B is a type for functions from A to B[x]. 19 / 61
  • 20. Dependent Types Dynamics in NLS DTS Conclusion From TTG to DTS: Compositionality Q: How could one get to these (dependently-typed) representations from arbitrary sentences? A: By lexicalization. Q: How could we lexicalize context-dependent words like pronouns?        u :    x : entity man(x) enter(x)    whistle( π1(u) )        20 / 61
  • 21. Dependent Types Dynamics in NLS DTS Conclusion Dependent Type Semantics (DTS) 21 / 61
  • 22. Dependent Types Dynamics in NLS DTS Conclusion From TTG to DTS: Compositionality Q: How could one get to these (dependently-typed) representations from arbitrary sentences? A: By lexicalization. Q: How could we lexicalize context-dependent words like pronouns? A: By using underspecified terms. Q: But how could we retrieve a context for an underspecified term? A: By type checking. 22 / 61
  • 23. Dependent Types Dynamics in NLS DTS Conclusion Underspecified terms DTS = DTT + underspecified terms @A Definition (@-rule) A : typej A true @iA : A where j ∈ N (@) I @-rule states that the well-formedness of @A requires: I A is a well-formed type. I the inhabitance of A (namely, A is a presuppositional content) 23 / 61
  • 24. Dependent Types Dynamics in NLS DTS Conclusion On parsing We assume that an SR of a sentence is obtained by parsing and semantic composition (assumed by one’s syntactic theory). A sentence ⇓ Parsing ⇓ An underspecified SRs in DTS 24 / 61
  • 25. Dependent Types Dynamics in NLS DTS Conclusion Lexical items in CCG-style PF CCG categories Semantic representations in DTS if S/S/S λp.λq. (u : p) → q everynom S/(SNP)/N λn.λp. u : x : entity nx → p(π1(u)) everyacc T (T /NP)/N λn.λp.λ~ x. v : y : entity ny → p(π1(v))~ x anom , somenom S/(SNP)/N λn.λp.   u : x : entity nx p(π1(u))   aacc, someacc T (T /NP)/N λn.λp.λ~ x.   v : y : entity ny p(π1(v))~ x   farmer N farmer donkey N donkey who NN/(SNP ) λp.λn.λx. nx px whom NN/(S/NP ) λp.λn.λx. nx px owns SNP/NP own beats SNP/NP beat he NP π1 @ x : entity male(x) ! it NP π1 @ x : entity ¬human(x) ! the NP/N λn.π1 @ x : entity nx ! 25 / 61
  • 26. Dependent Types Dynamics in NLS DTS Conclusion Lexical items in CCG-style (anaphoric expressions) PF CCG categories Semantic representations in DTS he NP π1 @ x : entity male(x) ! it NP π1 @ x : entity ¬human(x) ! the NP/N λn.π1 @ x : entity nx ! 26 / 61
  • 27. Dependent Types Dynamics in NLS DTS Conclusion E-type anaphora: Parsing A S/(SNP)/N : λn.λp.   u : x : entity nx p(π1u)   man N : λx.man(x) S/(SNP) : λp.   u : x : entity man(x) p(π1u)   entered SNP : λx.enter(x) S :   u : x : entity man(x) enter(π1u)   27 / 61
  • 28. Dependent Types Dynamics in NLS DTS Conclusion E-type anaphora: Parsing He NP : π1 @ x : entity male(x) whistled SNP : λx.whistle(x) S : whistle π1 @ x : entity male(x) ! 28 / 61
  • 29. Dependent Types Dynamics in NLS DTS Conclusion Progressive conjunction: Ranta (1994) Definition (Progressive conjunction) M; N def ≡ u : M N where u / ∈ fv(N) (9) [A man]1 entered. He 1 whistled.   x : entity man(x) enter(x)   ; whistle(π1 @ x : entity male(x) ) =        u :   x : entity man(x) enter(x)   whistle(π1 @ x : entity male(x) )        29 / 61
  • 30. Dependent Types Dynamics in NLS DTS Conclusion E-type anahora: Type checking . . .   u : x : entity man(x) enter(π1u)   : type whistle : entity → type (CON ) . . . x : entity male(x) : type v :   u : x : entity man(x) enter(π1u)   1 . . . . x : entity male(x) true @ x : entity male(x) : x : entity male(x) (@) π1 @ x : entity male(x) : entity (ΣE) whistle π1 @ x : entity male(x) ! : type (→E)        v :   u : x : entity man(x) enter(π1u)   x : entity !        : type (ΣF),1 30 / 61
  • 31. Dependent Types Dynamics in NLS DTS Conclusion E-type anaphora: Proof search v :   u : x : entity man(x) enter(π1u)   1 π1v : x : entity man(x) (ΣE) π1π1v : entity (ΣE) v :   u : x : entity man(x) enter(π1u)   1 π1v : x : entity man(x) (ΣE) m : u : x : entity man(x) → male(π1 m(π1v) : male(π1π1v) (π1π1v, m(π1v)) : x : entity male(x) (ΣE) 31 / 61
  • 32. Dependent Types Dynamics in NLS DTS Conclusion E-type anaphora: @-elimination . . . .   u : x : entity man(x) enter(π1u)   : type whistle : entity → type v :   u : x : entity man(x) enter(π1u)   1 . . . . (π1π1v, m(π1v)) : x : entity male(x) π1π1v : entity (ΣE) whistle( π1π1v ) : type (ΠE)     v :   u : x : entity man(x) enter(π1u)   whistle( π1π1v )     : type (ΣF),1 32 / 61
  • 33. Dependent Types Dynamics in NLS DTS Conclusion @-elimination rules Definition (@-elimination rules (excerpt)) u w vA : s DM M : A0 @iA : A (@) }  ~ = DM M : A0 u w w v DA A : s1 x : A0 DB B : s2 (x : A) → B : s2 (ΠF) }   ~ = JDAK A0 : s1 x : A0 JDBK B0 : s2 (x : A0) → B0 : s2 (ΠF) u w w v DA A : s1 x : A0 DM M : B λx.M : (x : A) → B (ΠI ) }   ~ = JDAK A0 : s1 x : A0 JDM K M0 : B0 λx.M0 : (x : A0) → B0 (ΠI ) u w v DM M : (x : A) → B DN N : A MN : B0 (ΠE) }  ~ = JDM K M0 : (x : A0) → B0 JDN K N0 : A0 M0N0 : B00 where B0[N0/x] β B00 (ΠE) 33 / 61
  • 34. Dependent Types Dynamics in NLS DTS Conclusion The model of language understanding A sentence . . . A sentence ⇓ ⇓ Parsing . . . Parsing ⇓ ⇓ An underspecified SRs in DTS . . . An underspecified SRs in DTS ⇓ ⇓ Discoruse relation (e.g. Progressive conjunction) ⇓ An underspecified discourse representation in DTS ⇓ Type checking + Proof search in DTS ⇓ A proof diagram of the well-formedness of an SR in DTS ⇓ @-elimination ⇓ A proof diagram of the well-formedness of an SR in DTT ⇓ Inference in DTT 34 / 61
  • 35. Dependent Types Dynamics in NLS DTS Conclusion Concluding Remarks 35 / 61
  • 36. Dependent Types Dynamics in NLS DTS Conclusion Compositional Theory of Anaphora I DTS provides a unified analysis for (general) inferences and anaphora resolusion mechanisms (at least) for: I Deictic use and coreference I Bound variable anaphora (BVA) I E-type anaphora I Donkey anaphora I Bridging anaphora I Syllogistic anaphora I Disjunctive antecedents 36 / 61
  • 37. Dependent Types Dynamics in NLS DTS Conclusion Compositional Theory of Anaphora I The background theory for DTS is an extention of DTT with underspecified terms and the @-rule . I Lexical items of anaphoric expressions and presupposition triggers are represented by using underspecified terms. I Context retrieval in DTS reduces to type checking . I Anaphora resolution and presupposition binding in DTS reduces to proof search . I @-elimination translates a proof diagram of DTS into a proof diagram of DTT, by which an SR in DTT is obtained with all anaphora resolved. 37 / 61
  • 38. Dependent Types Dynamics in NLS DTS Conclusion Natural language semantics via dependent types: Classics I Donkey anaphora: Sundholm (1986) I Translation from DRS to dependent type representations: Ahn and Kolb (1990) I Summation: Fox (1994a,b) I Ranta’s TTG (Relative and Implicational Donkey Sentences, Branching Quantifiers, Intensionality, Tense): Ranta (1994) I Translation from Montague Grammar to dependent type representations: Dávila-Pérez (1995) I Presupposition Binding and Accommodation, Bridging: Krahmer and Piwek (1999), Piwek and Krahmer (2000) 38 / 61
  • 39. Dependent Types Dynamics in NLS DTS Conclusion Natural language semantics via dependent types: Recent frameworks I Type Theory with Record (TTR): Cooper (2005) I Modern Type Theory: Luo (1997, 1999, 2010, 2012), Asher and Luo (2012), Chatzikyriakidis (2014) I Semantics with Dependent Types: Grudzinska and Zawadowski (2014; 2017) I Dependent Type Semantics (DTS): Bekki (2014), Bekki and Mineshima (2017) I (Dynamic Categorial Grammar: Martin and Pollard (2014)) 39 / 61
  • 40. Dependent Types Dynamics in NLS DTS Conclusion Semantic Analyses by DTS I Generalized Quantifiers: Tanaka (2014) I Honorification: Watanabe et al. (2014) I Conventional Implicature: Bekki and McCready (2015) I Factive Presuppositions: Tanaka et al. (2015)(2017) I Dependent Plural Anaphora: Tanaka et al. (2017) I Paycheck sentences: Tanaka et al. (2018) in NLCS2018 (July 7) I Coercion and Metaphor: Kinoshita et al. (2018) I Questions in Dependent Type Semantics: Watanabe et al. (NLCS’19) I Comparision with DRT: Yana et al. (2019) in JoLLI 40 / 61
  • 41. Dependent Types Dynamics in NLS DTS Conclusion Semantic Analyses by DTS I Development of an automated theorem prover for the fragment of DTS: Daido and Bekki (2020) in LENLS17 I A Proof-theoretic Analysis of Weak Crossover: Bekki (2021) in LENLS18 I The proviso problem from a proof-theoretic perspective: Yana et al. (2021) in LACL2021 I Integrating Deep Neural Network with Dependent Type Semantics: Bekki et al. (2021) in LACompLing2021 I Learning Knowledge with Neural DTS: Bekki et al. (2022) in NALOMA’22 41 / 61
  • 42. Dependent Types Dynamics in NLS DTS Conclusion Thank you! 42 / 61
  • 43. Typing Rules @-Elim. Rules References Typing Rules in DTS 43 / 61
  • 44. Typing Rules @-Elim. Rules References Axioms and Structural Rules A : type x : A (VAR) c : A (CON ) where σ ` c : A. M : A N : B M : A (WK) M : A M : B (CONV ) where A =β B. 44 / 61
  • 45. Typing Rules @-Elim. Rules References Π-type F/I/E rules A : type x : A i . . . . B : type (x : A) → B : type (ΠF),i A : type x : A i . . . . M : B λx.M : (x : A) → B (ΠI ),i M : (x : A) → B N : A MN : B[N/x] (ΠE) 45 / 61
  • 46. Typing Rules @-Elim. Rules References Σ-type F/I/E rules A : type x : A i . . . . B : type (x : A) × B : type (ΣF),i M : A N : B[M/x] (M, N) : (x : A) × B (ΣI ) M : (x : A) × B π1(M) : A (ΣE) M : (x : A) × B π2(M) : B[π1(M)/x] (ΣE) 46 / 61
  • 47. Typing Rules @-Elim. Rules References Disjoint Union Type F/I/E rules A : type B : type A ] B : type (]F) M : A ι1(M) : A ] B (]I ) N : B ι2(N) : A ] B (]I ) L : A ] B P : (A ] B) → type M : (x : A) → P (ι1(x)) N : (x unpackP L (M, N) : P (L) 47 / 61
  • 48. Typing Rules @-Elim. Rules References Natural Number Type F/I/E rules N : type (NF) 0 : N (NI ) n : N s(n) : N (NI ) n : N P : N → type e : P (0) f : (k : N) → P (k) → P (s(k)) natrecP n (e, f) : P (n) 48 / 61
  • 49. Typing Rules @-Elim. Rules References Enumeration Type F/I/E rules {a1, . . . , an} : type ({}F) ai : {a1, . . . , an} ({}I ) M : {a1, . . . , an} P : {a1, . . . , an} → type N1 : P (a1) . . . Nn : P (an) caseP M (N1, . . . , Nn) : P (M) ({}E) 49 / 61
  • 50. Typing Rules @-Elim. Rules References Intensional Equality Type F/I/E rules A : type M : A N : A M =A N : type (=F) A : type M : A reflA(M) : M =A M (=I ) E : M =A N P : (x : A) → (y : A) → (x =A y) → type R : (x : A) → P xx(reflA(x)) idpeelP E (R) : P MNE (= 50 / 61
  • 51. Typing Rules @-Elim. Rules References @-rule A : typej A true @iA : A where j ∈ N (@) 51 / 61
  • 52. Typing Rules @-Elim. Rules References @-Elimination Rules in DTS 52 / 61
  • 53. Typing Rules @-Elim. Rules References Axioms u w vA : s DM M : A0 @iA : A (@) }  ~ = DM M : A0 s c : A (CON ) { = c : A (CON ) r x : A z = x : A s type : kind (typeF) { = type : kind (typeF) 53 / 61
  • 54. Typing Rules @-Elim. Rules References Π-type u w w v DA A : s1 x : A0 DB B : s2 (x : A) → B : s2 (ΠF) }   ~ = JDAK A0 : s1 x : A0 JDBK B0 : s2 (x : A0) → B0 : s2 (ΠF) u w w v DA A : s1 x : A0 DM M : B λx.M : (x : A) → B (ΠI ) }   ~ = JDAK A0 : s1 x : A0 JDM K M0 : B0 λx.M0 : (x : A0) → B0 (ΠI ) u w v DM M : (x : A) → B DN N : A MN : B0 (ΠE) }  ~ = JDM K M0 : (x : A0) → B0 JDN K N0 : A0 M0N0 : B00 where B0[N0/x] β B00 (ΠE) 54 / 61
  • 55. Typing Rules @-Elim. Rules References Σ-type u w w w v DA A : s1 x : A0 DB B : s2 x : A B : s2 (ΣF) }    ~ = JDAK A0 : s1 x : A0 JDBK B0 : s2 x : A0 B0 : s2 (ΣF) u w w v DM M : A DN N : B0 (M, N) : x : A B (ΣI ) }   ~ = JDM K M0 : A0 JDN K N0 : B000 (M0, N0) : x : A0 B00 where B00[M0/x] β B000 (ΣI ) u w w w v DM M : x : A B π1(M) : A (ΣE) }    ~ = JDM K M0 : x : A0 B0 π1(M0) : A0 (ΣE) u w w w v DM M : x : A B π2(M) : B0 (ΣE) }    ~ = JDM K M0 : x : A0 B00 π2(M0) : B000 (ΣE) 55 / 61
  • 56. Typing Rules @-Elim. Rules References Reference I Ahn, R. and H.-P. Kolb. (1990) “Discourse Representation meets Constructive Mathematics”, In: L. Kalman and L. Polos (eds.): Papers from the Second Symposium on Logic and Language. Akademiai Kiado, pp.1–18. Asher, N. and Z. Luo. (2012) “Formalisation of coercions in lexical semantics”, In the Proceedings of Sinn und Bedeutung 17. pp.63–80. Bekki, D. (2014) “Representing Anaphora with Dependent Types”, In the Proceedings of N. Asher and S. V. Soloviev (eds.): Logical Aspects of Computational Linguistics (8th international conference, LACL2014, Toulouse, France, June 2014 Proceedings), LNCS 8535. pp.14–29, Springer, Heiderburg. 56 / 61
  • 57. Typing Rules @-Elim. Rules References Reference II Bekki, D. and E. McCready. (2015) “CI via DTS”, In: New Frontiers in Artificial Intelligence (JSAI-isAI 2014 Workshops, LENLS, JURISIN, and GABA, Yokohama, Japan, November 23-24, 2014, Revised Selected Papers), Vol. LNAI 9067. Springer, pp.23–36. Bekki, D. and K. Mineshima. (2017) “Context-passing and Underspecification in Dependent Type Semantics”, In: Modern Perspectives in Type Theoretical Semantics, Studies of Linguistics and Philosophy. Springer, pp.11–41. Chatzikyriakidis, S. (2014) “Adverbs in a Modern Type Theory”, In: N. Asher and S. V. Soloviev (eds.): Logical Aspect of Computational Linguistics, 8th International Conference, LACL2014, Toulouse, France, June 18-20, 2014 Proceedings. Springer. 57 / 61
  • 58. Typing Rules @-Elim. Rules References Reference III Cooper, R. (2005) “Records and Record Types in Semantic Theory”, Journal of Logic and Computation 15(2), pp.99–112. Dávila-Pérez, R. (1995) “Semantics and Parsing in Intuitionistic Categorial Grammar”, Thesis, University of Essex. Ph.D. thesis. Evans, G. (1980) “Pronouns”, Linguistic Inquiry 11, pp.337–362. Fox, C. (1994a) “Discourse Representation, Type Theory and Property Theory”, In the Proceedings of H. Bunt, R. Muskens, and G. Rentier (eds.): the International Workshop on Computational Semantics. pp.71–80. Fox, C. (1994b) “Existence Presuppositions and Category Mistakes”, Acta Linguistica Hungarica 42(3/4), pp.325–339. Geach, P. (1962) Reference and Generality: An Examination of Some Medieval and Modern Theories. Ithaca, New York, Cornell University Press. 58 / 61
  • 59. Typing Rules @-Elim. Rules References Reference IV Krahmer, E. and P. Piwek. (1999) “Presupposition Projection as Proof Construction”, In: H. Bunt and R. Muskens (eds.): Computing Meanings: Current Issues in Computational Semantics, Studies in Linguistics Philosophy Series. Dordrecht, Kluwer Academic Publishers. Luo, Z. (1997) “Coercive subtyping in type theory”, In: D. van Dalen and M. Bezem (eds.): CSL 1996. LNCS, vol. 1258. Heidelberg, Springer. Luo, Z. (1999) “Coercive subtyping”, Journal of Logic and Computation 9(1), pp.105–130. Luo, Z. (2010) “Type-theoretical semantics with coercive subtyping”, In the Proceedings of Semantics and Linguistic Theory 20 (SALT 20). 59 / 61
  • 60. Typing Rules @-Elim. Rules References Reference V Luo, Z. (2012) “Formal Semantics in Modern Type Theories with Coercive Subtyping”, Linguistics and Philosophy 35(6). Martin, S. and C. J. Pollard. (2014) “A dynamic categorial grammar”, In the Proceedings of Formal Grammar 19, LNCS 8612. Piwek, P. and E. Krahmer. (2000) “Presuppositions in Context: Constructing Bridges”, In: P. Bonzon, M. Cavalcanti, and R. Nossum (eds.): Formal Aspects of Context, Applied Logic Series. Dordrecht, Kluwer Academic Publishers. Ranta, A. (1994) Type-Theoretical Grammar. Oxford University Press. Sundholm, G. (1986) “Proof theory and meaning”, In: Handbook of Philosophical Logic, Vol. III. Reidel, Kluwer, pp.471–506. 60 / 61
  • 61. Typing Rules @-Elim. Rules References Reference VI Tanaka, R. (2014) “A Proof-Theoretic Approach to Generalized Quantifiers in Dependent Type Semantics”, In the Proceedings of R. de Haan (ed.): the ESSLLI 2014 Student Session, 26th European Summer School in Logic, Language and Information. pp.140–151. Tanaka, R., K. Mineshima, and D. Bekki. (2015) “Factivity and Presupposition in Dependent Type Semantics”, In the Proceedings of TYpe Theory and LExical Semantics (TYTLES), ESSLLI2015 workshop. Watanabe, N., E. McCready, and D. Bekki. (2014) “Japanese Honorification: Compositionality and Expressivity”, In the Proceedings of S. Kawahara and M. Igarashi (eds.): FAJL 7: Formal Approaches to Japanese Linguistics, the MIT Working Papers in Linguistics 73. pp.265–276. 61 / 61